کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
2006507 | 1066343 | 2011 | 6 صفحه PDF | دانلود رایگان |
We previously demonstrated that intrathecal treatment with substance P metabolite substance P1–7 induced anti-hyperalgesia in diabetic mice. In the present study, we have used a synthetic analog of this peptide, the substance P1–7 amide, showing higher binding affinitiy than the native heptapeptide, for studies of the tail-flick response in diabetic and non-diabetic mice. Intrathecal injection of substance P1–7 amide produced prolongation of the tail-flick latency in both diabetic and non-diabetic mice, an effect that was more pronounced in diabetic mice than non-diabetic mice. Moreover, the observed antinociceptive potency of the substance P1–7 amide was higher in both diabetic and non-diabetic mice in comparison with the native substance P1–7. The antinociceptive effect of substance P1–7 amide was reversed by naloxone but not by the selective opioid receptor antagonist β-funaltrexamine, naltrindole or nor-binaltorphimine, selective for the μ-, δ- or κ-opioid receptor, respectively. In addition, the antinociceptive effect induced by substance P1–7 amide was partly reversed by the σ1 receptor agonist (+)-pentazocine, suggesting a possible involvement of the σ1 receptor for the action of this peptide. These results suggest that the actions of substance P1–7 amide mimic the effects of the native substance P fragment but with higher potency and that the mechanisms for its action may involve the σ1 receptor system.
Research highlights▶ The substance P (1–7)-amide shows higher antinociceptive potency than the authentic heptapeptide. ▶ The antinociceptive effect of the substance P (1–7)-amide is blocked by naloxone. ▶ The effect of the substance P (1–7)-amide is not affected by selective opioid receptor antagonists. ▶ The antinociceptive effect of the substance P (1–7)-amide is reversed by a sigma receptor agonist.
Journal: Peptides - Volume 32, Issue 1, January 2011, Pages 93–98